Power factor computation system in harmonics distorted environment

摘要

A system for measuring a power factor in a harmonic distortion environment according to the present invention includes a voltage current measuring unit that measures a voltage and a current from a power line and a power factor measuring unit that measures a power factor using a voltage and a current having a pure basic frequency of 60 Hz except for harmonic components included in the voltage and the current that are measured by the voltage current measuring unit, wherein the voltage current measuring unit includes a voltage transformer that transforms electric power having high voltage, which is outputted by the power line, into electric power having low voltage, which is proportional to the electric power having high voltage, to measure a high voltage that is outputted by the power line, a current transformer that transforms electric power having high current, which is outputted by the power line, into electric power having low current, which is proportional to the electric power having high current, to measure high current that is outputted by the power line, an amplification unit that amplifies a signal that is outputted by the voltage transformer or the current transformer, an A/D convertor that converts an analog signal outputted by the amplification unit into digital data, and a voltage current measurement control unit that calculates the voltage and the current outputted by the power line using the digital data outputted by the A/D convertor. Thus, when the system for measuring a power factor in a harmonic distortion environment according to the present invention is applied to an automatic power factor control device, a power factor compensation performance in the harmonic distortion environment may be maximized.